Precise Box creation (migrating from 3d MAX)
A long winded answer.

Most primitive objects (the ones created by pressing ShiftA) will display a creation menu on the toolbar (T) that will allow you to precisely control dimensions and some variables for that particular object. The same menu is available by pressing F6

Example:



Note that this original creation menu is only available when you first create the object. Any transformation (move, size, etc) will freeze the object with those settings and pressing undo will not bring back the original menu. Any further transformation will have to be done by editing the mesh.

Now, down to the issue with your box.

Blender does not have options to create Cuboids with precise dimensions, so you're stuck with creating a cube. 

In the case of the cube there is just an option for radius, as is presumed that in a cube all edges will be the same length.

To create a cuboid you need to deform a cube in Object Mode to the desired dimensions, using the transform section.

Once you set the size it is very important to Apply the Transformation (press CtrlA).



Please read:

Why is it important to apply transformation to an objects data?

and

Why do the measurements of this object seem erroneous?